Jarring tools



June 12, 1956 R. M. TURNER JARRING TOOLS Filed Nov. 16, 1954 INVENTOR United States Patent JARRING TOOLS Ralph M. Turner, Rockville, Md.

Application November 16, 1954, Serial No. 469,229 Claims. c1. 1-47 This invention relates to new and useful improvements and structural refinements in jarring tools or percussion tools, and specifically, the invention concerns itself with a tool of this type which is adapted for convenient and expeditious attachment to a conventional electric drill to convert the rotary motion thereof into a reciprocating movement with a definite impact during each stroke, whereby the tool may be efiectively employed for driving nails or other similar operations,

The principal object of this invention is'to provide a tool of the character herein described which is very simple in construction, durable in operation and wherein the various moving parts are arranged concentrically or coaxially with the chuck of the drill to which the tool is attached, whereby to avoid undue strain and vibration which is present in other tools wherein the moving parts are axially unbalanced.

Another object of the invention is to provide a tool of the character herein described which embodies means for maintaining the same in engagement with the work, whereby to eliminate any possibility of the tool sliding or slipping off the work during the jarring movement.

With the above more important objects and features in view and such other objects and features as may become apparent as this specification proceeds, the invention resides in the arrangement of parts and details of construction substantially as shown in the accompanying drawing, wherein like characters of reference are employed to designate like parts and wherein:

Figure l is a longitudinal sectional view of the invention;

Figure 2 is a fragmentary sectional View thereof, taken substantially in the plane of the line 22 in Figure 1;

Figure 3 is a perspective view of the sleeve portion of the housing and the associated stationary cam member;

Figure 4 is a perspective view of another cam member;

Figure 5 is a perspective view of the adapter used in the invention;

Figure 6 is a perspective view of the extension stem; and I Figure 7 is a perspective viw of the work guiding sleeve.

Referring now to the accompanying drawing in detail, the jarring tool is designed generally by the numeral 10 and embodies in its construction an elongated housing consisting of a substantially cylindrical body 11 and a tubular extension sleeve 12 which is separately connected to the body 11 by screw threads 13. Also, a set screw 14 may be employed for securing the body and the sleeve against relative rotation.

The body 11 has an enlarged end portion 11a which is adapted to receive therein the housing of a conventional electric drill 15 so that the chuck 16 of the drill is disposed in the housing portion 11a, as shown. The body portion 11a is removably attached to the drill 15 by one or more set screws 17, which will be clearly apparent.

n 2,749,548 Ice PatentediJune 1 The body 11 is provided intermediate the ends thereof with a transverse partition 18 which is centrally apertured to afford a bearing for an adapter 19, the latter being rotatable in the body 11 and including a shank 20 which is operatively engageable with the drill chuck 16. The body 11 is provided at one side thereof with an opening 21 through which the customary key (not shown) may be inserted to tighten or loosen the drill chuck.

The adapter 19 is formed with a diametrically enlarged main body portion 22 disposed at one side of the partition 18, while a snap ring 23 is provided on the adapter at the opposite side of partition so as to prevent the adapter from longitudinal sliding movement. As will be noted, the snap ring 23 is accessible through the opening 21.

A transverse pin 24 is secured in the main body portion 22 of the adapter 19 and the end portions of this pin carry a pair of freely rotatable bearing rollers 25 which are operatively disposed in a pair of diametrically opposed slots 26 provided in a cam member 27. The latter is reciprocably positioned in the body 11 on the main body portion of the adapter, and it will be observed from the foregoing that the cam member 27 is slidable and rotatable with the adapter itself.

A second cam member 28 is formed integrally with the aforementioned sleeve 12 and is disposed stationarily in the housing 11in opposing relation to the cam member 27; Thus, when the cam member 27 is rotated by the adapter 19, the engaging lobes 27a and 28a of the respective cam members will impart a reciprocating movement to the cam member 27 while it slides on the adapter body portion 22 and the side-edges of the slots 26 slide along the rollers 25. Resilient means, hereinafter described, are employed for urging the cam member 27toward the cam member 28. Accordingly, when the high points 27b and 28b of the respective cam members clear each other, the resilient means will cause the cam member 27 to slide toward the cam member 28 with a quick, impact ing motion which is subsequently transmitted to the work.

The sleeve 12 afiords a bearing 29 for a reciprocable plunger 30 which extends through a counterbore 31 in the cam member 28 and is secured in the cam member 27 by a transverse pin 32, whereby the plunger is reciprocated together with the cam member 27. The other end of the plunger is equipped with an enlarged head 33 and a compression spring 34 is positioned on the plunger between the head 33 and the bearing 29, thus constituting the forementioned means for urging the cam member 27 toward the cam member 28.

In order that the tool may operate as quietly and smoothly as possible, a compression spring 35, substantially shorter and weaker than the spring 34, is positioned on the plunger 30 in the counterbore 31 and between the cam members 27, 28. This spring is free of compression when the cam members are separated and is compressed to a slight extent only when the cam members are brought fully together by the spring 34, in which manner the spring 35 functions as an effective shock absorber.

An extension unit designated generally by the numeral 36 is provided on the sleeve 12 of the housing 11 and includes a substantially tubular body 37 which is screwthreaded on the sleeve 12 as shown at 38 and is additionally secured thereto by a set screw 39. The body 37 accommodates a reciprocable stem 40 having an outer work engaging end 41 and an inner end provided with an enlarged head 42 formed integrally with a diametrically reduced cap 43. The latter is projectable into the sleeve 12 to abut the end of the plunger 30, while the head 42, engageable with the outer end of the sleeve 12, alfords stops means for preventing the stem 40 from travelling too far inwardly, Sufiicient space exists between the head 42 and the end of the sleeve 12 to permit entry of the cap 43 into the sleeve for operative engagement with the plunger head 33.

A work guiding sleeve 44 is slidably positioned in the outer end of the body 37 on the work engaging end portion of the stem 40 in a coaxial relation with the latter, the outer end portion of the sleeve 44 projecting outwardly from the body 37 while its inner end is formed with an outturned flange 45. A compression spring 46 is provided in the body 37 on the stem 40 between the flange 45 and the stem head 42, whereby the spring 46 performs a double function, namely, that of urging the sleeve 44 outwardly from the body 37 and urging the cap 43 in abutment with the plunger 30.

It will be noted that the sleeve 44 projects outwardly beyond the work engaging end 41 of the stem 40 and thus affords a work receiving socket, so to speak, which prevents the tool from sliding or slipping off the Work. As the work, such as a nail, or the like, is driven in by the tool, the sleeve 44 is automatically retracted into the body 37 against the action of the spring 46 when the outer end of the sleeve contacts the board, or the like, into which the nail is driven, and thus, the stem 40 is able to fully drive the nail in place without interference from the guiding sleeve.

If desired, suitable reduction gearing, or the like (not shown) may be provided in the housing portion 11a between the chuck 16 and the adapter shank 20, so that the tool is operated at a reduced speed.

Although in the foregoing there has been shown and described the preferred embodiment of the invention, various modifications may become apparent to those skilled in the art to which the invention relates. Accordingly, it is not desired to limit the invention to this disclosure and various modifications may be resorted to, such as may lie within the spirit and scope of the appended claims.

What is claimed as new is:

1. A jarring tool comprising in combination, an elongated housing adapted at one end thereof for attachment to an electric drill, a drill engaging adapter rotatably mounted in said housing, a cam member rotatable with and slidable relative to said adapter, a reciprocable plunger provided in said housing and connected to said cam member, a second cam member stationary in said housing and operatively engaged by the first mentioned cam member whereby to reciprocate said plunger, resilient means urging the first and second mentioned cam members together, a reciprocable extension unit provided in said housing, said extension unit having an outer work engaging end and an inner end operatively engaging said plunger, and a retractable work guide positioned slidably in and projecting outwardly from said housing in surrounding relation to the work engaging end of said extension.

2. In a jarring tool, the combination of an elongated housing adapted at one end thereof for attachment to an electric drill, an adapter rotatably mounted in said housing and including a main body portion and a drill engaging shank thereon, a cam member slidable in said housing longitudinally of said adapter, means operatively connecting said cam member to said adapter for rotation therewith, a reciprocable plunger provided in said housing and connected to said carn member, a second cam member stationary in the housing and operatively engaged by the first mentioned cam member whereby to reciprocate said plunger, resilient means positioned on said plunger for urging the first and second mentioned cam members together, a reciprocable extension unit provided in said housing, said extension unit having an outer work engaging end and an inner end in abutting engagement with said plunger, and a shock absorber provided between the first and second mentioned cam members.

3. The structure as set forth in claim 2 together with a retractable work guiding sleeve slidably positioned on the work engaging end of said extension and projecting outwardly from said housing, and resilient means for urging said sleeve to its projected position,

4. The structure as set forth in claim 2 together with a retractable work guiding sleeve slidably positioned on the work engaging end of said extension and projecting outwardly from said housing, and resilient means for simultaneously urging said sleeve to its projected position and urging said extension unit in abutment with said plunger.

5. The structure as set forth in claim 2 wherein said means operatively connecting said cam member to said adapter comprise a transverse pin carried by the main body portion of the adapter, and rollers provided on the end portions of said pin, said first mentioned cam member being provided with slots having said rollers movably disposed therein.

References Cited in the file of this patent UNITED STATES PATENTS 1,273,873 Kollock July 30, 1918 1,665,173 Misener Apr. 3, 1928 1,856,336 Hysing May 3, 1932 1,928,082 Vigne Sept. 26, 1933 2,009,580 Govanus July 30, 1935 2,657,383 Siering Nov. 3, 1953 

